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Well abandonment handbook

Well abandonment handbook 2002

Well Abandonment Handbook
Table of Contents
I. Introduction ............................................................................................................................ 1
II. Overview of the Well Abandonment Process ........................................................................ 2
III. Surface Seal Requirements Applicable to the Upper 20 Feet of All Wells to be Abandoned
and Special Requirements for Debris-Filled or Obstructed Wells......................................... 5
A. Surface Seal Requirements............................................................................................... 5
Surface Casing Removal Option ...................................................................................... 5
Surface Casing Non-Removal Option.............................................................................. 5
B. Special Requirements for Debris Filled or Obstructed Wells .......................................... 5
IV. Abandonment Methods .......................................................................................................... 5
A. Standard Abandonment Method....................................................................................... 5
B. Alternative Abandonment Methods.................................................................................. 6
Alternative 1 – Applies to wells that do not penetrate aquifers, including wells that have
gone dry, and no vadose zone contamination issues exist. .............................................. 6
Alternative 2 – Applies to wells that do not penetrate aquifers, including wells that have
gone dry, and vadose zone contamination issues exist. ................................................... 6
Alternative 3 – Applies to wells that penetrate single or multiple aquifers, and water
quality contamination issues exist.................................................................................... 6
Alternative 4 – Applies to wells that penetrate a single aquifer only without vertical
flow components, and no water quality contamination issues exist................................. 8
Alternative 4 (Variance Option)................................................................................. 8
Alternative 5 – Applies to wells that penetrate single or multiple aquifers with vertical
flow components, and no water quality contamination issues exist................................. 9
Alternative 5 (Variance Option 1).............................................................................. 9
Alternative 5 (Variance Option 2).............................................................................. 9
References ................................................................................................................................. 12
APPENDIX A – A.A.C. R12-15-816, The ADWR Well Abandonment Rule............................. 13
APPENDIX B – Definitions ......................................................................................................... 15
APPENDIX C – Questions and Answers about the Abandonment Handbook............................. 19
Figure 1 Well Abandonment Process .................................................................................... 4
Figure 2 Alternative Abandonment Methods Applicable to Five Commonly Occurring
Vadose Zone and Aquifer Conditions..................................................................... 7
Table 1 Acceptable Well Abandonment Materials and Mixtures ...................................... 11
Well Abandonment Handbook
Arizona Department of Water Resources 1
I. Introduction
The Arizona Department of Water
Resources (“ADWR”) regulates the
abandonment of wells in Arizona. ADWR
adopted a rule setting forth requirements for
well abandonment in 1984 and amended the
rule in 1990. The amended rule is published
in the Arizona Administrative Code
(“A.A.C.”) as Rule R12-15-816. A copy of
the rule is attached to this Handbook as
Appendix A.
ADWR’s well abandonment rule requires
that well abandonment be accomplished
“through filling or sealing the well so as to
prevent the well, including the annular space
outside the casing, from being a channel
allowing the vertical movement of water.”
A.A.C. R12-15-816(G). The rule prescribes
the fill materials that must be used in certain
aquifer conditions. A.A.C. R12-15-816(H).
The rule also requires the filing of a pre-abandonment
notice with ADWR (unless the
well is a new well being abandoned in the
course of drilling the well) and the filing of
post-abandonment reports. A.A.C. R12-15-
816(B), (E) and (F).
The purpose of this Handbook is to provide
a step-by-step guide to the abandonment of a
well in a manner that complies with
ADWR’s well abandonment rule. The
Handbook describes the abandonment
process from the filing of a Notice of
Intention to Abandon with ADWR prior to
commencing abandonment, to the filing of
post-abandonment reports by the well owner
and well driller. Most importantly, the
Handbook describes procedures that may be
used to adequately abandon a well,
including fill materials and emplacement
methods.
A standard abandonment method is
described that may be used for any well,
regardless of the aquifer and vadose zone
conditions applicable to the well. Five
alternative abandonment methods are also
described for five different vadose zone and
aquifer conditions. In most cases, the
alternative abandonment method will be less
expensive than the standard method.
However, a well owner may need to
demonstrate to ADWR that the well to be
abandoned falls within the condition to
which the alternative method applies before
that method may be used. For that reason,
the abandonment process may take longer if
an alternative abandonment method is
requested.
The well abandonment methods described in
this Handbook are presented in much greater
detail than in ADWR’s well abandonment
rule. However, the Handbook is not
intended to change any of the requirements
in the rule or to impose any additional
requirements. The purpose of including the
abandonment methods in the Handbook is to
assist well owners and well drillers in
complying with A.A.C. R12-15-816(G) by
informing them of fill materials and
emplacement methods ADWR considers to
be adequate to seal a well in a manner that
will prevent the well from being a channel
allowing the vertical movement of water. A
person who abandons a well in accordance
with the applicable well abandonment
method described in this Handbook will be
assured of complying with A.A.C. R12-15-
816(G).
The next section presents an overview of the
abandonment process. Section III describes
surface seal requirements for the upper 20
feet of all wells and special requirements for
debris-filled or obstructed wells. Section IV
describes the standard abandonment method
and the five alternative methods. Appendix
B contains definitions of terms used in this
Handbook and Appendix C contains
questions and answers regarding this
Handbook.
Well Abandonment Handbook
2 Arizona Department of Water Resources
II. Overview of the Well
Abandonment Process
Legal authorization from the ADWR is
required to abandon most types of wells in
the State of Arizona. The types of wells for
which abandonment authority from ADWR
is required are described in the question and
answer section of this Handbook (Appendix
C).
The process that must be followed to obtain
well abandonment authority starts with the
filing of a notice of intention to abandon a
well (NOIA) (see Figure 1). NOIA forms
may be obtained from the ADWR
Groundwater Management Support Section
office in Phoenix, or at local ADWR offices
located in Prescott, Casa Grande, Tucson
and Nogales. The NOIA form must be
signed and filed by the well owner.
However, the licensed well driller or a
consultant may assist the well owner in
filling out and filing the NOIA.
Information that must be submitted in the
NOIA form includes the following:
A well construction diagram showing all
existing well construction features and
the proposed abandonment
specifications.
A description of the type and condition
of the casing. Although this information
may not be completely known prior to
abandonment, this description should be
a “best estimate” of the conditions.
A description of the proposed method of
abandonment. The casing removal
techniques (such as pulling by hydraulic
jacks, overdrilling, etc.), or casing non-removal
techniques (such as casing
perforations, brushing, sonar jetting,
etc.) must be described. If the casing is
to be perforated, the perforation method,
size, and intervals to be perforated must
be described.
A description of the method of
emplacing the sealing or fill materials
(such as “tremie pumped” or “pressure
grouting”, etc.).
The specific type and estimated amount
of grout material to be used, and the
ratios of water, cement, and/or other
grout materials.
If the well owner or well driller has any
questions during the abandonment planning
stages prior to submittal of the NOIA, it is
recommended that they contact the ADWR
Hydrology Division. ADWR will gladly
work with the well owner or well driller to
answer any questions and conduct a
preliminary review of the proposed
abandonment plan. ADWR may be
contacted at:
602-417-2400
(Phoenix metro area)
1-800-352-8488
(outside metro Phoenix)
After the NOIA is filed, ADWR performs a
completeness review of the notice (See
Figure 1). The completeness review entails
the examination of the NOIA to determine if
all required information has been properly
submitted. After the ADWR determines that
the NOIA is complete, a substantive review
is performed to determine whether the
proposed abandonment methods and
materials meet the requirements of the
ADWR well abandonment rule (See Figure
1). If the standard method of abandonment
described on page 5 of this Handbook is
selected, which may be used for any well
regardless of the aquifer and vadose zone
conditions applicable to the well, the NOIA
will be approved without further review.
If an alternative abandonment method is
selected, the NOIA will receive additional
substantive review to determine whether the
Well Abandonment Handbook
Arizona Department of Water Resources 3
well falls within the condition to which the
alternative method applies and whether
appropriate fill materials were chosen.
During the review process ADWR may
contact the well owner to request additional
information or discuss modifications to the
proposed abandonment plan, if necessary.
Once the proposed well abandonment
methods and materials meet the
requirements of the abandonment rule, a
well abandonment authorization card is
mailed to the designated well driller and
well abandonment operations may begin
(See Figure 1).
Within 30 days after a well is abandoned,
the well owner is required to file a Well
Owner’s Notification of Abandonment; and
the well drilling contractor is required to file
a Well Abandonment Completion Report
with ADWR which describes the actual
methods and materials used to abandon the
well (See Figure 1). Information that must
be submitted in the Well Abandonment
Completion Report includes the following:
The specific type and amount of grout
and/or fill materials used as well as the
mixing ratio of water, cement and/or
other grout materials used.
A description of the type and condition
of the casing.
A description of the actual method of
abandonment. The casing removal
techniques (such as pulling by hydraulic
jacks, overdrilling, etc.), or casing non-removal
techniques (such as casing
perforations, brushing, sonar jetting,
etc.) must be described. If the casing
was perforated, the perforation method,
size, and intervals must be described.
A description of the method of
emplacing the sealing or fill materials
(such as “tremie pumped” or “pressure
grouting”, etc.).
The latitude, longitude and well
elevation of the abandoned well, and the
method used to determine these data.
Latitude and longitude coordinates
determined from readily available
Global Positioning System (GPS)
equipment are preferred because of the
high level of accuracy and comparative
ease of measurement. If GPS equipment
is used to determine these coordinates,
the general grade of equipment should
be specified (for example: survey grade
or hand-held). Latitude, longitude and
well elevation coordinates may also be
obtained from conventional surveying
methods or through estimation from a
topographic map.
Well Abandonment Handbook
4 Arizona Department of Water Resources
Figure 1
Well Abandonment Process
Well Abandonment Handbook
Arizona Department of Water Resources 5
III. Surface Seal Requirements
Applicable to the Upper 20 Feet
of All Wells to be Abandoned
and Special Requirements for
Debris-Filled or Obstructed
Wells
In addition to the well sealing and
abandonment methods and materials that are
discussed in the following section, ADWR’s
well abandonment rule requires a cement
grout surface seal (plug) to be installed in
the upper 20 feet of any well that is
abandoned. Special requirements may also
be necessary if casing obstructions and/or
debris hamper the abandonment of a well.
These requirements are described below:
A. Surface Seal Requirements
Surface Casing Removal Option
If the casing is removed from the top 20 feet
of the well, a cement grout plug must be set
extending from two feet below the land
surface to a minimum of twenty feet below
the land surface, and the well must be
backfilled above the top of the cement grout
plug to the original land surface.
Surface Casing Non-Removal Option
If the casing is not removed from the top 10
feet of the well, a cement grout plug must be
set extending from the top of the casing to a
minimum of twenty feet below the land
surface, and the annular space outside the
casing must be filled with cement from the
land surface to a minimum of twenty feet
below the land surface.
B. Special Requirements for
Debris Filled or Obstructed Wells
In situations where casing obstructions
and/or debris hamper well abandonment, the
problems should be indicated on the NOIA
form. In most instances a reasonable
attempt to clear debris and obstructions from
the well will be required. However, site-specific
conditions will determine the actual
method of abandonment.
IV. Abandonment Methods
A. Standard Abandonment
Method
The ADWR standard abandonment method
meets the requirements of ADWR’s well
abandonment rule under any given
combination of aquifer and vadose zone
conditions. The standard abandonment
method may be followed to obtain expedited
processing of an NOIA and issuance of a
well abandonment authority.
Under the standard abandonment method,
the entire length of well casing must be
removed or the entire length of the casing
must be reperforated (from 20 feet above the
highest historic water level to the total depth
of the well) with a minimum of two cuts per
foot. If it is determined that the disturbance
of the casing and/or gravel packed zones
would negatively influence the sealing of the
well, then an appropriate alternative
abandonment method must be used (see
Figure 2 for examples).
The well must be completely filled with neat
cement, cement-bentonite grout or, except
where free-product contamination is present,
high-solids bentonite grout (granular or
powder mixtures) with a minimum of 25%
solids by weight. Materials or mixtures
must be emplaced under sufficient pressure
to fill all voids, including all annular
space(s), and displace water from the well.
A tremie pipe must be used to emplace the
grout from the bottom up. The end of the
tremie pipe must remain in close proximity
to the rising grout surface, as the grout is
pumped into the well.
In order to receive expedited processing, the
NOIA should be filled out completely, and
the “Standard method” should be selected in
the proposed well abandonment method
section of the NOIA form. The specific type
Well Abandonment Handbook
6 Arizona Department of Water Resources
and estimated volume of grout material
should be specified on the NOIA form. Any
discrepancies between the estimated volume
of grout to be used, and the actual amount of
grout that was used for abandonment should
be reported and explained on the Well
Abandonment Completion Report.
B. Alternative Abandonment
Methods
There are five alternatives to the standard
abandonment method described above.
Each alternative method is designed for a
different vadose zone or aquifer condition,
and only one alternative method is
appropriate for a specific well. The
conditions described at the beginning of
each alternative and the depictions in Figure
2 should be carefully reviewed to determine
the appropriate alternative method if the
standard abandonment method is not
selected. If an alternative method is
selected, the method must be identified by
number in the NOIA and the well owner
may be required to submit information
demonstrating that the applicable vadose
zone or aquifer conditions exist for the well.
Alternative 1 – Applies to wells that
do not penetrate aquifers, including
wells that have gone dry, and no
vadose zone contamination issues
exist.
If the well does not penetrate an aquifer or
has gone dry, and vadose zone
contamination issues do not exist, the well
must be filled with one or more of the
following materials or mixtures: clean fine
sand, cement grout (including neat cement
grout, cement-bentonite grout and sand-cement
grout), concrete grout, sand-bentonite
grout, high-solids bentonite grout
(granular or powder mixtures) with a
minimum of 15% solids by weight, high-solids
bentonite chips or high-solids
bentonite pellets. See Table 1 for mixing
ratios. High-solids bentonite chips and
high-solids bentonite pellets must be
hydrated to manufacturer’s specifications.
The materials or mixtures are recommended
to exceed the casing volume by
approximately 30 percent.
In the course of drilling a new well, the well
may be abandoned using drill cuttings from
the well being drilled if the well does not
penetrate an aquifer, and no vadose zone
contamination issues exist.
Alternative 2 – Applies to wells that
do not penetrate aquifers, including
wells that have gone dry, and vadose
zone contamination issues exist.
If the well does not penetrate an aquifer or
has gone dry, and vadose zone
contamination issues exist, but there is no
free-product contamination, the well must be
filled with one or more of the following
materials or mixtures: cement grout
(including neat cement grout, cement-bentonite
grout and sand-cement grout),
concrete grout, sand-bentonite grout, high-solids
bentonite grout (granular or powder
mixtures) with a minimum of 15% solids by
weight, high-solids bentonite chips or high-solids
bentonite pellets. See Table 1 for
mixing ratios. High-solids bentonite chips
and high-solids bentonite pellets must be
hydrated to manufacturer’s specifications.
The materials or mixtures are recommended
to exceed the casing volume by
approximately 30 percent.
If free-product contamination issues exist,
the entire well must be sealed with neat
cement grout.
Alternative 3 – Applies to wells that
penetrate single or multiple aquifers,
and water quality contamination
issues exist.
If the well penetrates a single or multiple
aquifer system and water quality
contamination issues exist, then site-specific
conditions will determine the appropriate
seal material and emplacement method. The
seal material must be no more permeable
than the formation being sealed. A target
Well Abandonment Handbook
Arizona Department of Water Resources 7
Static Water Level
Upper Aquifer ?
Lower Aquifer
Upper Aquifer
Lower Aquifer
Vadose Zone or Vadose Zone
Depth to Aquifer
Boundary May or
May Not Be
Known
or
Vadose Zone
Contamination
Groundwater Contamination
Vertical Flow
Components
Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5
Wells That Do Not
Penetrate Aquifers
Including Wells That
Have Gone Dry
Wells That Do Not
Penetrate Aquifers
Including Wells That
Have Gone Dry
Wells That Penetrate
Single or Multiple
Aquifers
Wells That Penetrate
A Single Aquifer With
No Vertical Flow
Components
Wells That Penetrate
Single or Multiple
Aquifers With
Vertical Flow
Components
(No Vadose Zone
Contamination Issues
Exist)
(Vadose Zone
Contamination Issues
Exist)
(Water Quality
Contamination Issues
Exist)
(No Water Quality
Contamination Issues
Exist)
(No Water Quality
Contamination Issues
Exist)
Figure 2
Alternative Abandonment Methods Applicable to
Five Commonly Occurring Vadose Zone
and Aquifer Conditions
hydraulic conductivity of 10-7 cm/s may be
used for sealant materials. The types of
acceptable materials or mixtures are: cement
grout (including neat cement grout and
cement bentonite grout), high-solids
bentonite grout (granular or powder
mixtures) with a minimum of 15% solids by
weight, high-solids bentonite chips or high-solids
bentonite pellets. See Table 1 for
mixing ratios. A minimum of 15%
bentonite solids will be acceptable in most
cases. However, a higher minimum of
bentonite solids may be required in areas of
high water quality contamination. Acid
resistant cement (see definitions) may be
required in certain areas where corrosive
(low pH) groundwater conditions are
encountered. The materials or mixtures are
recommended to exceed the casing volume
by approximately 30 percent.
If there is no free-product contamination at
the well site, the vadose zone portion of the
well may be sealed with the same material
that is used to seal the well below the water
level. High-solids bentonite chips and high-solids
bentonite pellets must be hydrated to
manufacturer’s specifications if used in the
vadose zone. If free-product contamination
issues exist, the vadose zone portion of the
well must be sealed with neat cement grout.
Materials or mixtures must be emplaced
under sufficient pressure to fill all voids,
including all annular space(s), and displace
water from the well. A tremie pipe must be
used to emplace the grout from the bottom
up. The end of the tremie pipe shall remain
in close proximity to the rising grout surface
as the grout is pumped into the well.
Except as provided below for recently
constructed monitor wells, if the casing is
not removed, either the entire length of the
casing must be reperforated (from 20 feet
Well Abandonment Handbook
8 Arizona Department of Water Resources
above the highest historic water level to the
total depth of the well), or the condition of
the casing perforations must be determined
by running a video log that must be
submitted to the ADWR for review. If a
video log demonstrates that the existing
perforations are sufficiently open for grout
to enter the annular space outside the casing,
no additional perforations or casing
treatments will be required. If the video log
demonstrates that the existing perforations
are not sufficiently open for grout to enter
the annular space outside the casing,
additional perforations and/or casing
treatments such as mechanical brushing,
scraping or sonic cleaning will be required,
unless it is determined that disturbance of
the casing and/or gravel packed zones would
negatively influence the sealing of the well.
Casing perforation and/or casing cleaning
requirements for wells with water quality
contamination issues will be made by
ADWR on a case-by-case basis.
Wells requiring additional perforations must
be perforated a minimum of two cuts per
foot and sealed by pressure grouting. The
intervals to be perforated must be
determined based on site-specific
information. However, if no vadose zone
contamination issues exist, the perforations
need only extend 20 feet above the static
water level in the well.
Video logging and/or casing re-perforation
may not be required in the case of the
abandonment of recently constructed
monitor wells. However, that determination
must be made by ADWR on a case-by-case
basis.
Alternative 4 – Applies to wells that
penetrate a single aquifer only
without vertical flow components,
and no water quality contamination
issues exist.
If the well penetrates an aquifer and
hydrogeologic and stratigraphic information
is available for the well at an acceptable
level of confidence to determine that no
aquifer boundaries and no vertical flow
components exist within the length of the
well, and if water quality contamination
issues do not exist, the well must be filled
with one or more of the following materials
or mixtures: cement grout (including neat
cement grout, cement-bentonite grout and
sand-cement grout), concrete, high-solids
bentonite grout (granular or powder
mixtures) with a minimum of 15% solids by
weight, high-solids bentonite chips, high-solids
bentonite pellets, and sand-bentonite
grout. See Table 1 for mixing ratios.
In the course of drilling a new well, the well
may be abandoned using drill cuttings from
the well being drilled if the well does not
penetrate an aquifer, and no vadose zone
contamination issues exist.
The vadose zone portion of these types of
wells may be filled with any of the mixtures
or materials described above or allowed in
Alternative 1. High-solids bentonite chips
and high-solids bentonite pellets must be
hydrated to manufacturer’s specifications if
used in the vadose zone. The materials or
mixtures are recommended to exceed the
casing volume by approximately 30 percent.
Materials or mixtures must be emplaced
under sufficient pressure to fill all voids,
including all annular space(s), and displace
water from the well. A tremie pipe must be
used to emplace the grout from the bottom
up. The end of the tremie pipe shall remain
in close proximity to the rising grout surface
as the grout is pumped into the well.
Alternative 4 (Variance Option)
A variance option is available to abandon
wells that are 8 inches or greater in diameter
and that fall under Alternative 4 aquifer
conditions. Alternative 4 (Variance Option)
allows the use of clean fine sand to fill the
well.
Well Abandonment Handbook
Arizona Department of Water Resources 9
Please note that anyone wishing to use this
alternative abandonment method must first
apply to ADWR for a variance from the well
abandonment rule.
Alternative 5 – Applies to wells that
penetrate single or multiple aquifers
with vertical flow components, and
no water quality contamination
issues exist.
If the well penetrates a single or multiple
aquifer system with vertical flow
components, and if water quality
contamination issues do not exist, the well
must be sealed to prevent the vertical
migration of fluids with cement grout
(including neat cement grout, cement-bentonite
grout and sand-cement grout),
high-solids bentonite grout (granular or
powder mixtures) with a minimum of 15%
solids by weight, high-solids bentonite chips
or high-solids bentonite pellets of sufficient
volume, density, and viscosity to prevent
fluid communication between aquifers. See
Table 1 for mixing ratios.
The vadose zone portion of this type of well
may be filled with any of the mixtures or
materials described above or allowed in
Alternative 1. High-solids bentonite chips
and high-solids bentonite pellets must be
hydrated to manufacturer’s specifications if
used in the vadose zone. The materials or
mixtures are recommended to exceed the
casing volume by approximately 30 percent.
Materials or mixtures must be emplaced
under sufficient pressure to fill all voids,
including all annular space(s), and displace
water from the well. A tremie pipe must be
used to emplace the grout from the bottom
up. The end of the tremie pipe shall remain
in close proximity to the rising grout surface
as the grout is pumped into the well.
If the casing is not removed, it is
recommended, but not required, that the
condition of the casing perforations be
determined by running a video log. If the
video log demonstrates that the existing
perforations are sufficiently open for grout
to enter the annular space between the
casing and the well bore, no additional
perforations or casing treatments are
necessary. If the video log demonstrates
that the existing perforations are not
sufficiently open for grout to enter the
annular space outside the casing, additional
perforations and/or casing treatments such
as mechanical brushing, scraping or sonic
cleaning are recommended, unless it is
determined that disturbance of the casing
and/or gravel packed zones would
negatively influence the sealing of the well.
A well requiring additional perforations
should be perforated a minimum of two cuts
per foot and sealed by pressure grouting.
Alternative 5 (Variance Option 1)
Alternative 5 (Variance Option 1) is
available to abandon wells that are 8 inches
or greater in diameter and that fall under
Alternative 5 aquifer conditions. Alternative
5 (Variance option 1) allows the use of
alternating layers of 50 feet of clean, fine
sand and 10 feet of one of the approved
Alternative 5 materials or mixtures
mentioned above.
Please note that anyone wishing to use this
alternative abandonment method must first
apply to ADWR for a variance from
ADWR’s well abandonment rule.
Alternative 5 (Variance Option 2)
Alternative 5 (Variance Option 2) is
available to abandon wells that are 8 inches
or greater in diameter and that fall under
Alternative 5 aquifer conditions. Alternative
5 (Variance Option 2) allows the installation
of seals at aquifer boundaries if boundaries
exist and if hydrogeologic and stratigraphic
information is available for the well at an
acceptable level of confidence to determine
the depth(s) of aquifer boundaries. Aquifer
boundary seals must be composed of one of
the approved Alternative 5 materials or
mixtures mentioned above.
Well Abandonment Handbook
10 Arizona Department of Water Resources
Aquifer boundary seals must extend at least
50 feet above and 50 feet below aquifer
boundaries to provide a reasonable level of
confidence that the boundaries will be
sealed. The intervals of the well above and
below the seals must be filled with clean,
fine sand or one of the approved Alternative
5 materials or mixtures mentioned above.
Please note that anyone wishing to use this
alternative abandonment method must first
apply to ADWR for a variance from
ADWR’s well abandonment rule.
Well Abandonment Handbook
Arizona Department of Water Resources 11
Table 1
Acceptable Well Abandonment Materials and Mixtures
Mixing Ratio
Category
Specific Material
Solids Water
Permeability
(cm/sec)
Applicable
Abandonment
Methods
Special Considerations
Neat Cement
or
Neat Cement Grout
One 94 pound sack of
cement
Not more than six
(6) gallons water
10 –5
to
10 –7
Standard
Method and
Alts. 1-5
Must be pumped with tremie pipe.
Not for use in low pH environments.
Concrete
or
Concrete Grout
Cement, sand and
aggregate with no less
than seven (7) 94 lb.
sacks of cement per
cubic yard of concrete
Not more than
seven (7) gallons
water per sack of
cement
— Alts. 1,2,4,5 Cannot be used under Alternative 2 if free-product
contamination issues exist.
Sand-Cement Grout
One part cement and
no more than one part
sand by volume
Not more than six
(6) gallons water
2x10 –5
to
5x10 –8
Alts. 1,2,4,5 Cannot be used under Alternative 2 if free-product
contamination issues exist.
Cement-Bentonite
Grout
One sack of cement
(94 lb.) & 3-5 lbs.
bentonite
Not more than six
and one-half (6.5)
gallons water
10 –5
to
10 –11
Standard
Method and
Alts. 1-5
Cannot be used under Alternative 2 if free-product
contamination issues exist. Also
cannot be used in vadose zone portion of an
Alternative 3 well if free-product contamination
issues exist.
Sand-Bentonite Grout Equal parts sand and
bentonite by volume
Slightly more than
one (1) gallon
water per pound of
sand
— Alts. 1,2,4
May be difficult to pump; the sand may be
dumped into place while the bentonite slurry is
pumped via tremie pipe. Cannot be used
under Alternative 2 if free-product
contamination issues exist.
Cement, Sand, Concrete & Bentonite Mixtures 1
Acid Resistant
Cement
(Pozzolanic Cement)
One sack of cement
(94 lb.) and seventy-four
(74) lbs. pozzolans
(fly-ash, perlites, etc.)
2% to 6% of bentonite
by weight is needed if
perlites are used
Not more than ten
(10) gallons of
water per sack of
cement
— See special
considerations
Typically used in areas where low pH
groundwater is encountered. If perlites are
used bentonite is needed to keep perlites from
floating. Chemical admixtures and plastizers
may be used to reduce viscosity.
Well
Cuttings
Clean cuttings from
the well being drilled
and abandoned
NA NA — Alts. 1,4
Only permissible for wells that do not
penetrate aquifers or wells that only penetrate
a single aquifer with no vertical flow
components. No vadose zone and no water
quality contamination issues may exist.
High-Solids Bentonite
Grout (powder or
granular mixture) with
a minimum 15%
solids by weight
Minimum grout
density = 9.2
lbs./gallon
Fifty (50) lbs. dry
bentonite powder
(powder mixture)
or
One hundred fifty (150)
lbs. granular bentonite
& 1 qt. Polymer
(granular mixture)
Thirty–four
(34) gallons
(powder mixture)
or
One hundred
(100) gallons
(granular mixture)
10 –7
to
10 –8
Alts. 1-5
A minimum of 15% solids bentonite will be
acceptable in most cases. However, a higher
minimum of bentonite solids may be required
in areas of high water quality contamination.
Cannot be used under Alternative 2 if free-product
contamination issues exist. Also
cannot be used in vadose zone portion of an
Alternative 3 well if free-product contamination
issues exist. Granular mixtures generally
require the addition of polymers.
High-Solids Bentonite
Grout (powder or
granular mixture) with
a minimum 25%
solids by weight
Minimum grout
density = 10.0
lbs./gallon
Fifty (50) lbs. dry
bentonite powder
(powder mixture)
or
One hundred fifty (150)
lbs. granular bentonite
& 1 qt. Polymer
(granular mixture)
Eighteen
(18) gallons
(powder mixture)
or
Fifty-four
(54) gallons
(granular mixture)
10 –8
to
10 –9
Standard
Method
Cannot be used if free-product contamination
issues exist. Granular mixtures generally
require the addition of polymers.
Forms of Bentonite1,2
High-Solids Bentonite
Chips and Pellets NA NA — Alts. 1-5
Rate of pour should not exceed 50 lbs. / 5
minutes. Must be hydrated to manufacturer’s
specifications if used in vadose zone. Cannot
be used under Alternative 2 if free-product
contamination issues exist. Also cannot be
used in vadose zone portion of an Alternative
3 well if free-product contamination issues
exist.
Notes: 1) Additives will be considered on a case by case basis (i.e., fly ash, CaCl, etc.).
2) Manufacturer’s specifications should be followed to achieve a minimum 15% and 25% solids mixtures–mixing ratios listed in this table are
approximate.
Well Abandonment Handbook
12 Arizona Department of Water Resources
References
1. Alsay-Pippin Corporation, 1980,
Handbook of Industrial Drilling
Procedures and Techniques, 40 pp.
2. American Water Works Association,
1998, AWWA Standard for Water
Wells, ANSI/AWWA A100-97, 73 pp.
3. Arizona Department of Water
Resources, 2001, Statutes and Rules
Governing Minimum Well Construction
Standards and the Licensing of Well
Drillers, 32 pp.
4. American Society for Testing and
Materials (ASTM) Standard D5299-92,
1993, Standard Guide for
Decommissioning of Ground Water
Wells, Vadose Zone Monitoring
Devices, Boreholes, and Other Devices
for Environmental Activities, ASTM
1993 Annual Book of Standards, vol. 04-
08, p. 1318-1333.
5. Baroid Drilling Fluids, Inc., 1999,
Industrial Drilling Products Brochures,
Houston, Texas.
6. Burgin, M. J., et. al., 1988, Grouting
and Plugging of Domestic Water Wells
in Georgia, Department of Natural
Resources, Circular #13, 14 pp.
7. Driscoll, F.G., 1986, Groundwater and
Wells. 2nd edition, Johnson Filtration
Systems, St. Paul, Minnesota.
8. Eversoll, D.A., Hay, D. L., and
Tremblay, R. J, September 15, 1995,
Guidelines for Decommissioning Water
Wells, How to Plug Water Wells,
Nebraska Department of Health, Misc.
Publ #37, 22 pp.
9. Kurt, C.E. and Johnson, R.C., Jr., 1982,
Permeability of Grout Seals Surrounding
Thermoplastic Well Casing: Ground
Water, Vol. 20, no. 4, p. 415 - 419.
10. Lamb, B. and T. Kinney, 1989,
Decommissioning Wells - Techniques
and Pitfalls in Proceedings of the Third
National Outdoor Action Conference on
Aquifer Restoration, Ground Water
Monitoring and Geophysical Methods,
National Water Well Association,
Dublin, Ohio, p.217 - 228.
11. Lutenegger, A. J., and DeGroot, D. J.,
994, Hydraulic Conductivity of Borehole
Sealants in D.E. Daniel and S.J.
Trautwein (eds.), Hydraulic
Conductivity and Waste Contaminant
Transport in Soils, ASTM STP 1142,
Philadelphia, Pennsylvania, p. 439-460.
12. Michigan Department of Public Health,
Michigan Water Well Grouting Manual,
1988, 83 pp.
13. Portland Cement Association, 1988.
Design and Control of Concrete
Mixtures. 205 pp.
14. Smith, S.A., 1994. Well and Borehole
Sealing: Importance, Materials,
Methods, and Recommendations for
Decommissioning. EPA - 542/K94/005.
Wisconsin Water Well Association. 69
pp.
15. U.S. Environmental Protection Agency,
1975, Manual of Water Well
Construction Practices, EPA - 570/9-75-
001. 156 pp.
16. U.S. Environmental Protection Agency,
March 1991, Handbook of Suggested
Practices for the Design and Installation
of Ground-Water Monitoring Wells,
EPA- 600/4-89/034. 221 pp.
17. Wyo-Ben Inc., 1999, Groundwater &
Mineral Exploration Products Brochure.
Billings, Montana.
Well Abandonment Handbook
Arizona Department of Water Resources 13
APPENDIX A – A.A.C. R12-15-816, The ADWR Well Abandonment Rule
R12-15-816. Abandonment
A. Well abandonment shall be performed
only by a licensed well drilling
contractor or single well licensee.
B. Except as provided in subsection (F) of
this Section, the owner of a well shall
file a notice of intent to abandon the well
prior to abandonment, on a form
prescribed and furnished by the Director,
which shall include:
1. The name and mailing address of the
person filing the notice.
2. The legal description of the land upon
which the proposed well to be
abandoned is located and the name and
mailing address of the owner of the land.
3. The legal description of the location of
the well on the land.
4. The depth, diameter and type of casing
of the well.
5. The well registration number.
6. The materials and methods to be used to
abandon the well.
7. When abandonment is to begin.
8. The name and well drilling license of the
well drilling contractor or single well
licensee who is to abandon the well.
9. The reason for abandonment.
10. Such other information as the Director
may require.
C. The Director shall, upon receipt of a
proper notice of intent to abandon, mail
a well abandonment authorization card
to the designated well drilling contractor
or single well licensee.
D. Except as described in subsection (F) of
this section, a well drilling contractor or
a single well licensee may commence
abandoning a well only if the driller has
possession of an abandonment card at
the well site, issued by the Director in
the name of the driller, authorizing the
abandonment of that specific well or
wells in that specific location.
E. Within 30 days after a well is abandoned
pursuant to this Section, the well drilling
contractor or single well licensee shall
file with the Director a Well
Abandonment Completion Report on a
form prescribed and furnished by the
Director which shall include the date the
abandonment of the well was completed
and such other information as the
Director may require.
F. In the course of drilling a new well, the
well may be abandoned without first
filing a notice of intent to abandon and
without an abandonment card. If the
well is abandoned pursuant to this
subsection without first filing a notice of
intent to abandon and without an
abandonment card, the well drilling
contractor or single well licensee shall
provide the following information in the
Well Abandonment Completion Report:
1. The legal description of the land upon
which the well was abandoned and the
name and the mailing address of the
owner of the land.
2. The legal description of the location of
the well on the land.
3. The depth, diameter and type of casing
prior to abandonment.
4. The well registration number.
5. The materials and methods used to
abandon the well.
Well Abandonment Handbook
14 Arizona Department of Water Resources
6. The name and well drilling license
number of the well drilling contractor or
single well licensee who abandoned the
well.
7. The date of completion of the
abandonment of the well.
8. The reason for abandonment.
9. Such other information as the Director
may require.
G. The abandonment of a well shall be
accomplished through filing or sealing
the well so as to prevent the well,
including the annular space outside the
casing, from being a channel allowing
the vertical movement of water.
H. A well not penetrating an aquifer shall
include a surface seal which shall be
accomplished as follows:
1. If the casing is removed from the top 20
feet of the well, a cement grout plug
shall be set extending from two feet
below the land surface to a minimum of
twenty feet below the land surface, and
the well shall be backfilled above the top
of the cement grout plug to the original
land surface.
2. If the casing is not removed from the top
ten feet of the well, a cement grout plug
shall be set extending from the top of the
casing to a minimum of twenty feet
below the land surface, and the annular
space outside the casing shall be filled
with cement from the land surface to a
minimum of twenty feet below the land
surface.
I. In addition to the surface seal required in
subsection (H):
1. A well penetrating a single aquifer
system shall be filled with cement grout,
concrete, bentonite drilling muds, clean
sand with bentonite, or cuttings from the
well.
2. A well penetrating a single or multiple
aquifer system with vertical flow
components shall be sealed with cement
grout or a column of bentonite drilling
mud of sufficient volume, density, and
viscosity to prevent fluid communication
between aquifers.
J. Materials containing organic or toxic
matter shall not be used in the
abandonment of a well.
K. The owner or operator of the well shall
notify the Director in writing no later
than 30 days after abandonment has been
completed. The notification shall
include the well owner’s name, the
location of the well, and the method of
abandonment.
Well Abandonment Handbook
Arizona Department of Water Resources 15
APPENDIX B – Definitions
For the purposes of this Handbook, the
following terms have the following
meanings:
Acid Resistant Cement (also known as
Pozzolanic cement) (generic mixture):
means a cement mixture that has improved
resistance to corrosive fluids. Acid resistant
cement is developed by adding silicious
materials, pozzolans, to Portland cement.
Pozzolans from both natural materials of
volcanic origin such as perlites (volcanic
ashes), heat treated clays, shales, tuffs,
opaline cherts and diatomaceous earth, and
artificial materials consisting of by-products
from glass factories, furnace slag, and fly
ash may be used. A common mixing ratio is
74 pounds of pozzolans per 94 pound sack
of cement and not more than ten (10) gallons
of water per sack of cement. If perlites are
used, 2 to 6 percent of bentonite by weight is
needed to keep the perlite from floating.
Acid resistant cement is typically
recommended for well abandonment
material in areas where low pH groundwater
is encountered (such as near some mine
sites).
Aggregate (generic mixture): means sand
or gravel with particle size up to ¼ inch.
Annular Space: “means the space between
the outer well casing and the borehole wall.
An annular space also means the space
between an inner well casing and an outer
well casing.” A.A.C. R12-15-801(1)
Aquifer: “means an underground formation
capable of yielding or transmitting usable
quantities of water.” A.A.C. R12-15-801(2)
Aquifer Boundary: means a vertical
change in aquifer properties indicated by a
difference in hydraulic conductivity between
aquifer layers that is at least greater than two
orders of magnitude (100 times greater).
Bentonite “means a colloidal clay
composed mainly of sodium
montmorillonite, a hydrated aluminum
silicate.” A.A.C. R12-15-801(5)
Cement Grout or Grout: “means cement
mixed with no more than 50 percent sand by
volume, and containing no more than six
gallons of water per 94 pound sack of
cement.” A.A.C. R12-15-801(15)
Cement grout is sometimes referred to as
“sand-cement grout”, when sand is in the
mixture.
Grout is often used as a synonym for slurry
which is a generic term that means a thin
mixture of liquid, commonly water, and any
of several finely divided substances such as
cement or clay particles.
Cement-Bentonite Grout (generic
mixture): means a mixture of cement,
bentonite and water at a ratio of 6.5 gallons
of water per each 94 pound sack of cement
with not more than 3 to 5 pounds of
bentonite per sack of cement.
Concrete or Concrete Grout (generic
mixture): means a mixture of cement, sand,
coarse aggregate and water, with not less
than seven (7) 94 pound sacks of cement per
cubic yard of mixture and not more than
seven (7) gallons of water per sack of
cement.
Exploration Well: “means a well drilled in
search of geophysical, mineralogical, or
geotechnical data”. A.A.C. R12-15-801(13)
Free-Product Contamination: means any
known hazardous substance that is
essentially immiscible (non-soluble) in
water. Some typical examples of free-product
contamination are gasoline and
carbon tetrachloride.
Well Abandonment Handbook
16 Arizona Department of Water Resources
Hazardous Substance: has the same
meaning prescribed by A.R.S. § 49-201.
High-Solids Bentonite Grout (granular or
powder mixture) with a minimum of 15%
solids by weight: means a mixture of
granular bentonite or powder bentonite that
yields a grout that has a minimum 15%
bentonite solids by weight.
High-solids bentonite grout with a minimum
of 15% solids by weight can be prepared
from a mixture of granular bentonite
(nominal 8 to 20-mesh particle size), water
and polymer at a ratio of one hundred-fifty
(150) pounds of granular bentonite and one
hundred (100) gallons of water premixed
with one (1) quart of polymer.
High-solids bentonite grout with a minimum
of 15% solids by weight can also be
prepared from a mixture of bentonite
powder (nominal 200-mesh particle size)
and water at a ratio of fifty (50) pounds of
dry bentonite powder and thirty-four (34)
gallons of water.
High-Solids Bentonite Grout (granular or
powder mixture) with a minimum of 25%
solids by weight: means a mixture of
granular bentonite or powder bentonite that
yields a grout that has a minimum 25%
bentonite solids by weight.
High-solids bentonite grout with a minimum
of 25% solids by weight can be prepared
from a mixture of granular bentonite
(nominal 8 to 20-mesh particle size), water
and polymer at a ratio of one hundred-fifty
(150) pounds of granular bentonite and fifty-four
(54) gallons of water premixed with
one (1) quart of polymer.
High-solids bentonite grout with a minimum
of 25% solids by weight can also be
prepared from a mixture of bentonite
powder (nominal 200-mesh particle size)
and water at a ratio of fifty (50) pounds of
dry bentonite powder and eighteen (18)
gallons of water.
High-Solids Bentonite Chips: means chips
of coarse bentonite ranging in size from 0.25
to 0.75 inch.
High-Solids Bentonite Pellets: means
pellets of fine compressed bentonite (200-
mesh) ranging in size from 0.25 to 0.50
inch.
Neat Cement or Neat Cement Grout
(generic mixture): means a mixture of one
(1) 94 pound sack of cement with not more
than six (6) gallons of clean water.
Pressure Grouting “means a process by
which a grout is confined within the
borehole or casing of a well by the use of
retaining plugs, packers, or a displacing
fluid by which sufficient pressure is applied
to drive the grout into and within the annular
space or interval to be grouted.” A.A.C.
R12-15-801(23)
Sand-Bentonite Grout (generic mixture):
means a mixture of equal parts sand and
bentonite by volume with slightly more than
one (1) gallon of water per pound of sand.
Sand-Cement Grout (generic mixture):
means a mixture of one 94 pound sack of
Portland cement, sand and water in the
proportion of not more than one (1) part by
volume of sand to one (1) part of cement
with not more than six (6) gallons of water
per 94 pound sack of cement.
Sealing: means the conscious effort to
construct a positive permanent barrier within
a well that restricts or prohibits the vertical
movement of groundwater and/or any other
fluids or materials.
Vadose Zone Well “means a well
constructed in the interval between the land
surface and the top of the static water level.”
A.A.C. R12-15-801(26)
Well Abandonment Handbook
Arizona Department of Water Resources 17
Vadose Zone Contamination Issue: means
any hazardous substance that is found in the
vadose zone at or in the vicinity of the well
at concentrations that exceed established
state or federal standards.
Water Quality Contamination Issue:
means any known hazardous substance that
is found in groundwater at or in the vicinity
of the well at concentrations that exceed
established state or federal standards.
Well: means any man-made opening in the
earth through which water may be
withdrawn or obtained from beneath the
surface of the earth including: 1) all water
wells, monitor wells and piezometer wells;
2) geothermal wells for which the rules of
the Arizona Oil and Gas Commission do not
require the reinjection of all water associated
with the geothermal resource to the
producing strata; and 3) all exploration wells
and grounding or cathodic protection holes,
except those that are less than 100 feet in
depth and do not encounter groundwater.
The question and answer section of this
Handbook contains additional information
concerning the types of wells that are
subject to ADWR’s well abandonment rule.
Well Abandonment “means the
modification of the structure of a well by
filling or sealing the borehole so that water
may not be withdrawn or obtained from the
well.” A.A.C. R12-15-801(28)
Well Abandonment Handbook
18 Arizona Department of Water Resources
Well Abandonment Handbook
Arizona Department of Water Resources 19
APPENDIX C – Questions and Answers about the Abandonment
Handbook
Why was it necessary to provide a separate
well abandonment Handbook when there is
an existing well abandonment rule?
ADWR has become aware of some
misunderstanding among well owners and
well drillers concerning the requirements of
the well abandonment rule, A.C.C. R12-15-
816. This Handbook is intended to provide
guidance to well owners and well drillers on
what is required by the rule.
In addition, this Handbook describes the
procedures and materials that should be used
to abandon wells not detailed in the rule.
The well abandonment rule requires a
person abandoning a well to fill or seal the
well in order to prevent the well, including
the annular space outside the casing, from
being a channel allowing the vertical
movement of water. Any well owner or
well driller who abandons a well in
compliance with this Handbook will be
deemed to be in compliance with this
requirement.
Q. What types of wells are subject to
ADWR’s well abandonment rule?
A. The well abandonment rule applies to
man-made openings in the earth through
which water may be withdrawn or
obtained from beneath the surface of the
earth, including all water wells, monitor
wells and piezometer wells.
The well abandonment rule also applies
to geothermal wells for which the rules
and regulations of the Arizona Oil and
Gas Commission do not require the
reinjection of all waters associated with
the geothermal resource to the producing
strata, as well as exploration wells and
grounding or cathodic protection holes
greater than 100 feet in depth (regardless
of whether they intercept groundwater).
Q. What types of openings in the earth are
not subject to ADWR’s well
abandonment rule?
A. The well abandonment rule does not
apply to:
1. man-made openings in the earth not
commonly considered to be wells,
such as construction and mining
blast holes, underground mines and
mine shafts, open pit mines, tunnels,
septic tank systems, caissons,
basements, and natural gas storage
cavities;
2. an injection well or vadose zone well
that is subject to regulation by the
Arizona Department of
Environmental Quality (ADEQ),
provided that ADEQ has issued a
letter or other document asserting
explicit regulatory authority over the
well;
3. oil, gas, and helium wells drilled
pursuant to the provisions of Title
27, Arizona Revised Statutes (wells
regulated by the Arizona Oil and Gas
Commission); and
4. boreholes in the earth less than 100
feet in depth which are made for
purposes other than withdrawing or
encountering groundwater (such as
exploration wells and grounding or
cathodic protection holes less than
100 feet in depth), except that if
groundwater is encountered in the
drilling of the borehole, the well
abandonment rule will apply.
Although the well abandonment rule
does not apply to these types of wells
and boreholes, it is nevertheless
recommended that unused wells or
Well Abandonment Handbook
20 Arizona Department of Water Resources
boreholes that are not regulated under
ADWR’s well abandonment rule be
abandoned in a manner that will protect
the aquifer.
Q. What is the benefit of abandoning an
unused well, as opposed to capping the
well (which is also allowed under
ADWR’s rules)?
A. Proper well abandonment is favored
over well capping for both
environmental and safety reasons.
Unused and unabandoned wells
constitute actual or potential
environmental hazards because they can
serve as vertical conduits for hazardous
substances to cross-contaminate
aquifers. For example, during the last
several decades, serious and costly
vertical cross-contamination of a
multiple aquifer system has occurred
through unabandoned conduit wells at
the Indian Bend Wash Superfund site in
Scottsdale, Arizona. Owners of unused,
unabandoned wells should also realize
that they may be held legally responsible
for secondary contamination if it is
demonstrated that their well served as a
conduit for vertical cross-contamination
of an aquifer system.
Public safety issues also favor well
abandonment over well capping.
Capped wells are often tampered with,
and once the well cap is removed there is
a real danger for humans or animals to
fall into the well, or for the well to be
used for the illegal disposal of hazardous
materials.
Q. Why is it generally required to run a
video log to determine the condition of
the casing perforations in areas where
water quality contamination exists if
the casing is not ripped?
A. Because significant conduit flow can
occur through the annular space outside
the casing, it is essential to seal this
pathway to prevent potential vertical
cross-contamination. Therefore, when
water quality contamination issues exist,
unless the well casing is removed or the
casing is re-perforated over its entire
length from 20 feet above the highest
historic water level to the total depth of
the well, the well owner must run a
video log to determine whether the grout
material can flow through the casing
perforations and seal the annular space
outside the casing.
Video logging and/or casing re-perforation
may not be required in the
case of the abandonment of recently
constructed monitor wells. However,
that determination must be made on a
case-by-case basis.
In areas where water quality
contamination issues do not exist, if the
casing is not ripped, a video log is
recommended, although not required, to
determine perforation conditions. It is
important to make sure that the well and
the annular space outside the casing are
properly abandoned even when there are
no current water quality contamination
issues. This is because the water could
become contaminated in the future.
It should also be pointed out that
additional benefits can be derived from
running a video log. Those benefits may
include: the determination of the
structural integrity of the well casing, the
presence of casing anomalies and
obstructions, the presence of perched or
cascading water, etc. This information
can be very important in developing an
effective abandonment design.
Q. Under what circumstances is it
permissible to use drill cuttings to
abandon a well?
Well Abandonment Handbook
Arizona Department of Water Resources 21
A. In the course of drilling a new well, the
well may be abandoned using drill
cuttings from the well being drilled only
if the well does not penetrate an aquifer
or the well penetrates a single aquifer
only, with no vertical flow components.
Drill cuttings may only be used to
abandon the well from which they were
originally removed. Drill cuttings may
not be used to abandon wells or
boreholes that have water quality and/or
vadose zone contamination issues.
Q. How can it be determined whether
vertical flow components exist in an
aquifer or aquifer system?
A. The determination of vertical flow
conditions in an aquifer can be a
challenging task. However, vertical
flow conditions can be assessed by
evaluating water level data collected in
piezometers or monitor wells that are
completed at different depths within an
aquifer or aquifer system at the same
location. Vertical fluid movement can
also be evaluated in non-pumping wells
using various geophysical logging
techniques such as flowmeter logging,
spinner logging or tracer logging. The
observation of cascading water or water
seeping into a non-pumping well below
static level is a clear indication of
vertical flow conditions within the well.
Because unit-specific water level data
are typically unavailable, and
geophysical logging may be impractical
or too costly, it is best to assume that
most aquifers or aquifer systems have
some component of vertical flow, and
well abandonment methods and
materials should be chosen accordingly.
Q. What should I do if I have further
questions concerning a well
abandonment project?
A. Contact ADWR Hydrology Division at:
602-417-2400
(Phoenix metro area)
1-800-352-8488
(outside metro Phoenix)

Copyright to this resource is held by the creating agency and is provided here for educational purposes only. It may not be downloaded, reproduced or distributed in any format without written permission of the creating agency. Any attempt to circumvent the access controls placed on this file is a violation of United States and international copyright laws, and is subject to criminal prosecution.

Well Abandonment Handbook
Table of Contents
I. Introduction ............................................................................................................................ 1
II. Overview of the Well Abandonment Process ........................................................................ 2
III. Surface Seal Requirements Applicable to the Upper 20 Feet of All Wells to be Abandoned
and Special Requirements for Debris-Filled or Obstructed Wells......................................... 5
A. Surface Seal Requirements............................................................................................... 5
Surface Casing Removal Option ...................................................................................... 5
Surface Casing Non-Removal Option.............................................................................. 5
B. Special Requirements for Debris Filled or Obstructed Wells .......................................... 5
IV. Abandonment Methods .......................................................................................................... 5
A. Standard Abandonment Method....................................................................................... 5
B. Alternative Abandonment Methods.................................................................................. 6
Alternative 1 – Applies to wells that do not penetrate aquifers, including wells that have
gone dry, and no vadose zone contamination issues exist. .............................................. 6
Alternative 2 – Applies to wells that do not penetrate aquifers, including wells that have
gone dry, and vadose zone contamination issues exist. ................................................... 6
Alternative 3 – Applies to wells that penetrate single or multiple aquifers, and water
quality contamination issues exist.................................................................................... 6
Alternative 4 – Applies to wells that penetrate a single aquifer only without vertical
flow components, and no water quality contamination issues exist................................. 8
Alternative 4 (Variance Option)................................................................................. 8
Alternative 5 – Applies to wells that penetrate single or multiple aquifers with vertical
flow components, and no water quality contamination issues exist................................. 9
Alternative 5 (Variance Option 1).............................................................................. 9
Alternative 5 (Variance Option 2).............................................................................. 9
References ................................................................................................................................. 12
APPENDIX A – A.A.C. R12-15-816, The ADWR Well Abandonment Rule............................. 13
APPENDIX B – Definitions ......................................................................................................... 15
APPENDIX C – Questions and Answers about the Abandonment Handbook............................. 19
Figure 1 Well Abandonment Process .................................................................................... 4
Figure 2 Alternative Abandonment Methods Applicable to Five Commonly Occurring
Vadose Zone and Aquifer Conditions..................................................................... 7
Table 1 Acceptable Well Abandonment Materials and Mixtures ...................................... 11
Well Abandonment Handbook
Arizona Department of Water Resources 1
I. Introduction
The Arizona Department of Water
Resources (“ADWR”) regulates the
abandonment of wells in Arizona. ADWR
adopted a rule setting forth requirements for
well abandonment in 1984 and amended the
rule in 1990. The amended rule is published
in the Arizona Administrative Code
(“A.A.C.”) as Rule R12-15-816. A copy of
the rule is attached to this Handbook as
Appendix A.
ADWR’s well abandonment rule requires
that well abandonment be accomplished
“through filling or sealing the well so as to
prevent the well, including the annular space
outside the casing, from being a channel
allowing the vertical movement of water.”
A.A.C. R12-15-816(G). The rule prescribes
the fill materials that must be used in certain
aquifer conditions. A.A.C. R12-15-816(H).
The rule also requires the filing of a pre-abandonment
notice with ADWR (unless the
well is a new well being abandoned in the
course of drilling the well) and the filing of
post-abandonment reports. A.A.C. R12-15-
816(B), (E) and (F).
The purpose of this Handbook is to provide
a step-by-step guide to the abandonment of a
well in a manner that complies with
ADWR’s well abandonment rule. The
Handbook describes the abandonment
process from the filing of a Notice of
Intention to Abandon with ADWR prior to
commencing abandonment, to the filing of
post-abandonment reports by the well owner
and well driller. Most importantly, the
Handbook describes procedures that may be
used to adequately abandon a well,
including fill materials and emplacement
methods.
A standard abandonment method is
described that may be used for any well,
regardless of the aquifer and vadose zone
conditions applicable to the well. Five
alternative abandonment methods are also
described for five different vadose zone and
aquifer conditions. In most cases, the
alternative abandonment method will be less
expensive than the standard method.
However, a well owner may need to
demonstrate to ADWR that the well to be
abandoned falls within the condition to
which the alternative method applies before
that method may be used. For that reason,
the abandonment process may take longer if
an alternative abandonment method is
requested.
The well abandonment methods described in
this Handbook are presented in much greater
detail than in ADWR’s well abandonment
rule. However, the Handbook is not
intended to change any of the requirements
in the rule or to impose any additional
requirements. The purpose of including the
abandonment methods in the Handbook is to
assist well owners and well drillers in
complying with A.A.C. R12-15-816(G) by
informing them of fill materials and
emplacement methods ADWR considers to
be adequate to seal a well in a manner that
will prevent the well from being a channel
allowing the vertical movement of water. A
person who abandons a well in accordance
with the applicable well abandonment
method described in this Handbook will be
assured of complying with A.A.C. R12-15-
816(G).
The next section presents an overview of the
abandonment process. Section III describes
surface seal requirements for the upper 20
feet of all wells and special requirements for
debris-filled or obstructed wells. Section IV
describes the standard abandonment method
and the five alternative methods. Appendix
B contains definitions of terms used in this
Handbook and Appendix C contains
questions and answers regarding this
Handbook.
Well Abandonment Handbook
2 Arizona Department of Water Resources
II. Overview of the Well
Abandonment Process
Legal authorization from the ADWR is
required to abandon most types of wells in
the State of Arizona. The types of wells for
which abandonment authority from ADWR
is required are described in the question and
answer section of this Handbook (Appendix
C).
The process that must be followed to obtain
well abandonment authority starts with the
filing of a notice of intention to abandon a
well (NOIA) (see Figure 1). NOIA forms
may be obtained from the ADWR
Groundwater Management Support Section
office in Phoenix, or at local ADWR offices
located in Prescott, Casa Grande, Tucson
and Nogales. The NOIA form must be
signed and filed by the well owner.
However, the licensed well driller or a
consultant may assist the well owner in
filling out and filing the NOIA.
Information that must be submitted in the
NOIA form includes the following:
A well construction diagram showing all
existing well construction features and
the proposed abandonment
specifications.
A description of the type and condition
of the casing. Although this information
may not be completely known prior to
abandonment, this description should be
a “best estimate” of the conditions.
A description of the proposed method of
abandonment. The casing removal
techniques (such as pulling by hydraulic
jacks, overdrilling, etc.), or casing non-removal
techniques (such as casing
perforations, brushing, sonar jetting,
etc.) must be described. If the casing is
to be perforated, the perforation method,
size, and intervals to be perforated must
be described.
A description of the method of
emplacing the sealing or fill materials
(such as “tremie pumped” or “pressure
grouting”, etc.).
The specific type and estimated amount
of grout material to be used, and the
ratios of water, cement, and/or other
grout materials.
If the well owner or well driller has any
questions during the abandonment planning
stages prior to submittal of the NOIA, it is
recommended that they contact the ADWR
Hydrology Division. ADWR will gladly
work with the well owner or well driller to
answer any questions and conduct a
preliminary review of the proposed
abandonment plan. ADWR may be
contacted at:
602-417-2400
(Phoenix metro area)
1-800-352-8488
(outside metro Phoenix)
After the NOIA is filed, ADWR performs a
completeness review of the notice (See
Figure 1). The completeness review entails
the examination of the NOIA to determine if
all required information has been properly
submitted. After the ADWR determines that
the NOIA is complete, a substantive review
is performed to determine whether the
proposed abandonment methods and
materials meet the requirements of the
ADWR well abandonment rule (See Figure
1). If the standard method of abandonment
described on page 5 of this Handbook is
selected, which may be used for any well
regardless of the aquifer and vadose zone
conditions applicable to the well, the NOIA
will be approved without further review.
If an alternative abandonment method is
selected, the NOIA will receive additional
substantive review to determine whether the
Well Abandonment Handbook
Arizona Department of Water Resources 3
well falls within the condition to which the
alternative method applies and whether
appropriate fill materials were chosen.
During the review process ADWR may
contact the well owner to request additional
information or discuss modifications to the
proposed abandonment plan, if necessary.
Once the proposed well abandonment
methods and materials meet the
requirements of the abandonment rule, a
well abandonment authorization card is
mailed to the designated well driller and
well abandonment operations may begin
(See Figure 1).
Within 30 days after a well is abandoned,
the well owner is required to file a Well
Owner’s Notification of Abandonment; and
the well drilling contractor is required to file
a Well Abandonment Completion Report
with ADWR which describes the actual
methods and materials used to abandon the
well (See Figure 1). Information that must
be submitted in the Well Abandonment
Completion Report includes the following:
The specific type and amount of grout
and/or fill materials used as well as the
mixing ratio of water, cement and/or
other grout materials used.
A description of the type and condition
of the casing.
A description of the actual method of
abandonment. The casing removal
techniques (such as pulling by hydraulic
jacks, overdrilling, etc.), or casing non-removal
techniques (such as casing
perforations, brushing, sonar jetting,
etc.) must be described. If the casing
was perforated, the perforation method,
size, and intervals must be described.
A description of the method of
emplacing the sealing or fill materials
(such as “tremie pumped” or “pressure
grouting”, etc.).
The latitude, longitude and well
elevation of the abandoned well, and the
method used to determine these data.
Latitude and longitude coordinates
determined from readily available
Global Positioning System (GPS)
equipment are preferred because of the
high level of accuracy and comparative
ease of measurement. If GPS equipment
is used to determine these coordinates,
the general grade of equipment should
be specified (for example: survey grade
or hand-held). Latitude, longitude and
well elevation coordinates may also be
obtained from conventional surveying
methods or through estimation from a
topographic map.
Well Abandonment Handbook
4 Arizona Department of Water Resources
Figure 1
Well Abandonment Process
Well Abandonment Handbook
Arizona Department of Water Resources 5
III. Surface Seal Requirements
Applicable to the Upper 20 Feet
of All Wells to be Abandoned
and Special Requirements for
Debris-Filled or Obstructed
Wells
In addition to the well sealing and
abandonment methods and materials that are
discussed in the following section, ADWR’s
well abandonment rule requires a cement
grout surface seal (plug) to be installed in
the upper 20 feet of any well that is
abandoned. Special requirements may also
be necessary if casing obstructions and/or
debris hamper the abandonment of a well.
These requirements are described below:
A. Surface Seal Requirements
Surface Casing Removal Option
If the casing is removed from the top 20 feet
of the well, a cement grout plug must be set
extending from two feet below the land
surface to a minimum of twenty feet below
the land surface, and the well must be
backfilled above the top of the cement grout
plug to the original land surface.
Surface Casing Non-Removal Option
If the casing is not removed from the top 10
feet of the well, a cement grout plug must be
set extending from the top of the casing to a
minimum of twenty feet below the land
surface, and the annular space outside the
casing must be filled with cement from the
land surface to a minimum of twenty feet
below the land surface.
B. Special Requirements for
Debris Filled or Obstructed Wells
In situations where casing obstructions
and/or debris hamper well abandonment, the
problems should be indicated on the NOIA
form. In most instances a reasonable
attempt to clear debris and obstructions from
the well will be required. However, site-specific
conditions will determine the actual
method of abandonment.
IV. Abandonment Methods
A. Standard Abandonment
Method
The ADWR standard abandonment method
meets the requirements of ADWR’s well
abandonment rule under any given
combination of aquifer and vadose zone
conditions. The standard abandonment
method may be followed to obtain expedited
processing of an NOIA and issuance of a
well abandonment authority.
Under the standard abandonment method,
the entire length of well casing must be
removed or the entire length of the casing
must be reperforated (from 20 feet above the
highest historic water level to the total depth
of the well) with a minimum of two cuts per
foot. If it is determined that the disturbance
of the casing and/or gravel packed zones
would negatively influence the sealing of the
well, then an appropriate alternative
abandonment method must be used (see
Figure 2 for examples).
The well must be completely filled with neat
cement, cement-bentonite grout or, except
where free-product contamination is present,
high-solids bentonite grout (granular or
powder mixtures) with a minimum of 25%
solids by weight. Materials or mixtures
must be emplaced under sufficient pressure
to fill all voids, including all annular
space(s), and displace water from the well.
A tremie pipe must be used to emplace the
grout from the bottom up. The end of the
tremie pipe must remain in close proximity
to the rising grout surface, as the grout is
pumped into the well.
In order to receive expedited processing, the
NOIA should be filled out completely, and
the “Standard method” should be selected in
the proposed well abandonment method
section of the NOIA form. The specific type
Well Abandonment Handbook
6 Arizona Department of Water Resources
and estimated volume of grout material
should be specified on the NOIA form. Any
discrepancies between the estimated volume
of grout to be used, and the actual amount of
grout that was used for abandonment should
be reported and explained on the Well
Abandonment Completion Report.
B. Alternative Abandonment
Methods
There are five alternatives to the standard
abandonment method described above.
Each alternative method is designed for a
different vadose zone or aquifer condition,
and only one alternative method is
appropriate for a specific well. The
conditions described at the beginning of
each alternative and the depictions in Figure
2 should be carefully reviewed to determine
the appropriate alternative method if the
standard abandonment method is not
selected. If an alternative method is
selected, the method must be identified by
number in the NOIA and the well owner
may be required to submit information
demonstrating that the applicable vadose
zone or aquifer conditions exist for the well.
Alternative 1 – Applies to wells that
do not penetrate aquifers, including
wells that have gone dry, and no
vadose zone contamination issues
exist.
If the well does not penetrate an aquifer or
has gone dry, and vadose zone
contamination issues do not exist, the well
must be filled with one or more of the
following materials or mixtures: clean fine
sand, cement grout (including neat cement
grout, cement-bentonite grout and sand-cement
grout), concrete grout, sand-bentonite
grout, high-solids bentonite grout
(granular or powder mixtures) with a
minimum of 15% solids by weight, high-solids
bentonite chips or high-solids
bentonite pellets. See Table 1 for mixing
ratios. High-solids bentonite chips and
high-solids bentonite pellets must be
hydrated to manufacturer’s specifications.
The materials or mixtures are recommended
to exceed the casing volume by
approximately 30 percent.
In the course of drilling a new well, the well
may be abandoned using drill cuttings from
the well being drilled if the well does not
penetrate an aquifer, and no vadose zone
contamination issues exist.
Alternative 2 – Applies to wells that
do not penetrate aquifers, including
wells that have gone dry, and vadose
zone contamination issues exist.
If the well does not penetrate an aquifer or
has gone dry, and vadose zone
contamination issues exist, but there is no
free-product contamination, the well must be
filled with one or more of the following
materials or mixtures: cement grout
(including neat cement grout, cement-bentonite
grout and sand-cement grout),
concrete grout, sand-bentonite grout, high-solids
bentonite grout (granular or powder
mixtures) with a minimum of 15% solids by
weight, high-solids bentonite chips or high-solids
bentonite pellets. See Table 1 for
mixing ratios. High-solids bentonite chips
and high-solids bentonite pellets must be
hydrated to manufacturer’s specifications.
The materials or mixtures are recommended
to exceed the casing volume by
approximately 30 percent.
If free-product contamination issues exist,
the entire well must be sealed with neat
cement grout.
Alternative 3 – Applies to wells that
penetrate single or multiple aquifers,
and water quality contamination
issues exist.
If the well penetrates a single or multiple
aquifer system and water quality
contamination issues exist, then site-specific
conditions will determine the appropriate
seal material and emplacement method. The
seal material must be no more permeable
than the formation being sealed. A target
Well Abandonment Handbook
Arizona Department of Water Resources 7
Static Water Level
Upper Aquifer ?
Lower Aquifer
Upper Aquifer
Lower Aquifer
Vadose Zone or Vadose Zone
Depth to Aquifer
Boundary May or
May Not Be
Known
or
Vadose Zone
Contamination
Groundwater Contamination
Vertical Flow
Components
Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5
Wells That Do Not
Penetrate Aquifers
Including Wells That
Have Gone Dry
Wells That Do Not
Penetrate Aquifers
Including Wells That
Have Gone Dry
Wells That Penetrate
Single or Multiple
Aquifers
Wells That Penetrate
A Single Aquifer With
No Vertical Flow
Components
Wells That Penetrate
Single or Multiple
Aquifers With
Vertical Flow
Components
(No Vadose Zone
Contamination Issues
Exist)
(Vadose Zone
Contamination Issues
Exist)
(Water Quality
Contamination Issues
Exist)
(No Water Quality
Contamination Issues
Exist)
(No Water Quality
Contamination Issues
Exist)
Figure 2
Alternative Abandonment Methods Applicable to
Five Commonly Occurring Vadose Zone
and Aquifer Conditions
hydraulic conductivity of 10-7 cm/s may be
used for sealant materials. The types of
acceptable materials or mixtures are: cement
grout (including neat cement grout and
cement bentonite grout), high-solids
bentonite grout (granular or powder
mixtures) with a minimum of 15% solids by
weight, high-solids bentonite chips or high-solids
bentonite pellets. See Table 1 for
mixing ratios. A minimum of 15%
bentonite solids will be acceptable in most
cases. However, a higher minimum of
bentonite solids may be required in areas of
high water quality contamination. Acid
resistant cement (see definitions) may be
required in certain areas where corrosive
(low pH) groundwater conditions are
encountered. The materials or mixtures are
recommended to exceed the casing volume
by approximately 30 percent.
If there is no free-product contamination at
the well site, the vadose zone portion of the
well may be sealed with the same material
that is used to seal the well below the water
level. High-solids bentonite chips and high-solids
bentonite pellets must be hydrated to
manufacturer’s specifications if used in the
vadose zone. If free-product contamination
issues exist, the vadose zone portion of the
well must be sealed with neat cement grout.
Materials or mixtures must be emplaced
under sufficient pressure to fill all voids,
including all annular space(s), and displace
water from the well. A tremie pipe must be
used to emplace the grout from the bottom
up. The end of the tremie pipe shall remain
in close proximity to the rising grout surface
as the grout is pumped into the well.
Except as provided below for recently
constructed monitor wells, if the casing is
not removed, either the entire length of the
casing must be reperforated (from 20 feet
Well Abandonment Handbook
8 Arizona Department of Water Resources
above the highest historic water level to the
total depth of the well), or the condition of
the casing perforations must be determined
by running a video log that must be
submitted to the ADWR for review. If a
video log demonstrates that the existing
perforations are sufficiently open for grout
to enter the annular space outside the casing,
no additional perforations or casing
treatments will be required. If the video log
demonstrates that the existing perforations
are not sufficiently open for grout to enter
the annular space outside the casing,
additional perforations and/or casing
treatments such as mechanical brushing,
scraping or sonic cleaning will be required,
unless it is determined that disturbance of
the casing and/or gravel packed zones would
negatively influence the sealing of the well.
Casing perforation and/or casing cleaning
requirements for wells with water quality
contamination issues will be made by
ADWR on a case-by-case basis.
Wells requiring additional perforations must
be perforated a minimum of two cuts per
foot and sealed by pressure grouting. The
intervals to be perforated must be
determined based on site-specific
information. However, if no vadose zone
contamination issues exist, the perforations
need only extend 20 feet above the static
water level in the well.
Video logging and/or casing re-perforation
may not be required in the case of the
abandonment of recently constructed
monitor wells. However, that determination
must be made by ADWR on a case-by-case
basis.
Alternative 4 – Applies to wells that
penetrate a single aquifer only
without vertical flow components,
and no water quality contamination
issues exist.
If the well penetrates an aquifer and
hydrogeologic and stratigraphic information
is available for the well at an acceptable
level of confidence to determine that no
aquifer boundaries and no vertical flow
components exist within the length of the
well, and if water quality contamination
issues do not exist, the well must be filled
with one or more of the following materials
or mixtures: cement grout (including neat
cement grout, cement-bentonite grout and
sand-cement grout), concrete, high-solids
bentonite grout (granular or powder
mixtures) with a minimum of 15% solids by
weight, high-solids bentonite chips, high-solids
bentonite pellets, and sand-bentonite
grout. See Table 1 for mixing ratios.
In the course of drilling a new well, the well
may be abandoned using drill cuttings from
the well being drilled if the well does not
penetrate an aquifer, and no vadose zone
contamination issues exist.
The vadose zone portion of these types of
wells may be filled with any of the mixtures
or materials described above or allowed in
Alternative 1. High-solids bentonite chips
and high-solids bentonite pellets must be
hydrated to manufacturer’s specifications if
used in the vadose zone. The materials or
mixtures are recommended to exceed the
casing volume by approximately 30 percent.
Materials or mixtures must be emplaced
under sufficient pressure to fill all voids,
including all annular space(s), and displace
water from the well. A tremie pipe must be
used to emplace the grout from the bottom
up. The end of the tremie pipe shall remain
in close proximity to the rising grout surface
as the grout is pumped into the well.
Alternative 4 (Variance Option)
A variance option is available to abandon
wells that are 8 inches or greater in diameter
and that fall under Alternative 4 aquifer
conditions. Alternative 4 (Variance Option)
allows the use of clean fine sand to fill the
well.
Well Abandonment Handbook
Arizona Department of Water Resources 9
Please note that anyone wishing to use this
alternative abandonment method must first
apply to ADWR for a variance from the well
abandonment rule.
Alternative 5 – Applies to wells that
penetrate single or multiple aquifers
with vertical flow components, and
no water quality contamination
issues exist.
If the well penetrates a single or multiple
aquifer system with vertical flow
components, and if water quality
contamination issues do not exist, the well
must be sealed to prevent the vertical
migration of fluids with cement grout
(including neat cement grout, cement-bentonite
grout and sand-cement grout),
high-solids bentonite grout (granular or
powder mixtures) with a minimum of 15%
solids by weight, high-solids bentonite chips
or high-solids bentonite pellets of sufficient
volume, density, and viscosity to prevent
fluid communication between aquifers. See
Table 1 for mixing ratios.
The vadose zone portion of this type of well
may be filled with any of the mixtures or
materials described above or allowed in
Alternative 1. High-solids bentonite chips
and high-solids bentonite pellets must be
hydrated to manufacturer’s specifications if
used in the vadose zone. The materials or
mixtures are recommended to exceed the
casing volume by approximately 30 percent.
Materials or mixtures must be emplaced
under sufficient pressure to fill all voids,
including all annular space(s), and displace
water from the well. A tremie pipe must be
used to emplace the grout from the bottom
up. The end of the tremie pipe shall remain
in close proximity to the rising grout surface
as the grout is pumped into the well.
If the casing is not removed, it is
recommended, but not required, that the
condition of the casing perforations be
determined by running a video log. If the
video log demonstrates that the existing
perforations are sufficiently open for grout
to enter the annular space between the
casing and the well bore, no additional
perforations or casing treatments are
necessary. If the video log demonstrates
that the existing perforations are not
sufficiently open for grout to enter the
annular space outside the casing, additional
perforations and/or casing treatments such
as mechanical brushing, scraping or sonic
cleaning are recommended, unless it is
determined that disturbance of the casing
and/or gravel packed zones would
negatively influence the sealing of the well.
A well requiring additional perforations
should be perforated a minimum of two cuts
per foot and sealed by pressure grouting.
Alternative 5 (Variance Option 1)
Alternative 5 (Variance Option 1) is
available to abandon wells that are 8 inches
or greater in diameter and that fall under
Alternative 5 aquifer conditions. Alternative
5 (Variance option 1) allows the use of
alternating layers of 50 feet of clean, fine
sand and 10 feet of one of the approved
Alternative 5 materials or mixtures
mentioned above.
Please note that anyone wishing to use this
alternative abandonment method must first
apply to ADWR for a variance from
ADWR’s well abandonment rule.
Alternative 5 (Variance Option 2)
Alternative 5 (Variance Option 2) is
available to abandon wells that are 8 inches
or greater in diameter and that fall under
Alternative 5 aquifer conditions. Alternative
5 (Variance Option 2) allows the installation
of seals at aquifer boundaries if boundaries
exist and if hydrogeologic and stratigraphic
information is available for the well at an
acceptable level of confidence to determine
the depth(s) of aquifer boundaries. Aquifer
boundary seals must be composed of one of
the approved Alternative 5 materials or
mixtures mentioned above.
Well Abandonment Handbook
10 Arizona Department of Water Resources
Aquifer boundary seals must extend at least
50 feet above and 50 feet below aquifer
boundaries to provide a reasonable level of
confidence that the boundaries will be
sealed. The intervals of the well above and
below the seals must be filled with clean,
fine sand or one of the approved Alternative
5 materials or mixtures mentioned above.
Please note that anyone wishing to use this
alternative abandonment method must first
apply to ADWR for a variance from
ADWR’s well abandonment rule.
Well Abandonment Handbook
Arizona Department of Water Resources 11
Table 1
Acceptable Well Abandonment Materials and Mixtures
Mixing Ratio
Category
Specific Material
Solids Water
Permeability
(cm/sec)
Applicable
Abandonment
Methods
Special Considerations
Neat Cement
or
Neat Cement Grout
One 94 pound sack of
cement
Not more than six
(6) gallons water
10 –5
to
10 –7
Standard
Method and
Alts. 1-5
Must be pumped with tremie pipe.
Not for use in low pH environments.
Concrete
or
Concrete Grout
Cement, sand and
aggregate with no less
than seven (7) 94 lb.
sacks of cement per
cubic yard of concrete
Not more than
seven (7) gallons
water per sack of
cement
— Alts. 1,2,4,5 Cannot be used under Alternative 2 if free-product
contamination issues exist.
Sand-Cement Grout
One part cement and
no more than one part
sand by volume
Not more than six
(6) gallons water
2x10 –5
to
5x10 –8
Alts. 1,2,4,5 Cannot be used under Alternative 2 if free-product
contamination issues exist.
Cement-Bentonite
Grout
One sack of cement
(94 lb.) & 3-5 lbs.
bentonite
Not more than six
and one-half (6.5)
gallons water
10 –5
to
10 –11
Standard
Method and
Alts. 1-5
Cannot be used under Alternative 2 if free-product
contamination issues exist. Also
cannot be used in vadose zone portion of an
Alternative 3 well if free-product contamination
issues exist.
Sand-Bentonite Grout Equal parts sand and
bentonite by volume
Slightly more than
one (1) gallon
water per pound of
sand
— Alts. 1,2,4
May be difficult to pump; the sand may be
dumped into place while the bentonite slurry is
pumped via tremie pipe. Cannot be used
under Alternative 2 if free-product
contamination issues exist.
Cement, Sand, Concrete & Bentonite Mixtures 1
Acid Resistant
Cement
(Pozzolanic Cement)
One sack of cement
(94 lb.) and seventy-four
(74) lbs. pozzolans
(fly-ash, perlites, etc.)
2% to 6% of bentonite
by weight is needed if
perlites are used
Not more than ten
(10) gallons of
water per sack of
cement
— See special
considerations
Typically used in areas where low pH
groundwater is encountered. If perlites are
used bentonite is needed to keep perlites from
floating. Chemical admixtures and plastizers
may be used to reduce viscosity.
Well
Cuttings
Clean cuttings from
the well being drilled
and abandoned
NA NA — Alts. 1,4
Only permissible for wells that do not
penetrate aquifers or wells that only penetrate
a single aquifer with no vertical flow
components. No vadose zone and no water
quality contamination issues may exist.
High-Solids Bentonite
Grout (powder or
granular mixture) with
a minimum 15%
solids by weight
Minimum grout
density = 9.2
lbs./gallon
Fifty (50) lbs. dry
bentonite powder
(powder mixture)
or
One hundred fifty (150)
lbs. granular bentonite
& 1 qt. Polymer
(granular mixture)
Thirty–four
(34) gallons
(powder mixture)
or
One hundred
(100) gallons
(granular mixture)
10 –7
to
10 –8
Alts. 1-5
A minimum of 15% solids bentonite will be
acceptable in most cases. However, a higher
minimum of bentonite solids may be required
in areas of high water quality contamination.
Cannot be used under Alternative 2 if free-product
contamination issues exist. Also
cannot be used in vadose zone portion of an
Alternative 3 well if free-product contamination
issues exist. Granular mixtures generally
require the addition of polymers.
High-Solids Bentonite
Grout (powder or
granular mixture) with
a minimum 25%
solids by weight
Minimum grout
density = 10.0
lbs./gallon
Fifty (50) lbs. dry
bentonite powder
(powder mixture)
or
One hundred fifty (150)
lbs. granular bentonite
& 1 qt. Polymer
(granular mixture)
Eighteen
(18) gallons
(powder mixture)
or
Fifty-four
(54) gallons
(granular mixture)
10 –8
to
10 –9
Standard
Method
Cannot be used if free-product contamination
issues exist. Granular mixtures generally
require the addition of polymers.
Forms of Bentonite1,2
High-Solids Bentonite
Chips and Pellets NA NA — Alts. 1-5
Rate of pour should not exceed 50 lbs. / 5
minutes. Must be hydrated to manufacturer’s
specifications if used in vadose zone. Cannot
be used under Alternative 2 if free-product
contamination issues exist. Also cannot be
used in vadose zone portion of an Alternative
3 well if free-product contamination issues
exist.
Notes: 1) Additives will be considered on a case by case basis (i.e., fly ash, CaCl, etc.).
2) Manufacturer’s specifications should be followed to achieve a minimum 15% and 25% solids mixtures–mixing ratios listed in this table are
approximate.
Well Abandonment Handbook
12 Arizona Department of Water Resources
References
1. Alsay-Pippin Corporation, 1980,
Handbook of Industrial Drilling
Procedures and Techniques, 40 pp.
2. American Water Works Association,
1998, AWWA Standard for Water
Wells, ANSI/AWWA A100-97, 73 pp.
3. Arizona Department of Water
Resources, 2001, Statutes and Rules
Governing Minimum Well Construction
Standards and the Licensing of Well
Drillers, 32 pp.
4. American Society for Testing and
Materials (ASTM) Standard D5299-92,
1993, Standard Guide for
Decommissioning of Ground Water
Wells, Vadose Zone Monitoring
Devices, Boreholes, and Other Devices
for Environmental Activities, ASTM
1993 Annual Book of Standards, vol. 04-
08, p. 1318-1333.
5. Baroid Drilling Fluids, Inc., 1999,
Industrial Drilling Products Brochures,
Houston, Texas.
6. Burgin, M. J., et. al., 1988, Grouting
and Plugging of Domestic Water Wells
in Georgia, Department of Natural
Resources, Circular #13, 14 pp.
7. Driscoll, F.G., 1986, Groundwater and
Wells. 2nd edition, Johnson Filtration
Systems, St. Paul, Minnesota.
8. Eversoll, D.A., Hay, D. L., and
Tremblay, R. J, September 15, 1995,
Guidelines for Decommissioning Water
Wells, How to Plug Water Wells,
Nebraska Department of Health, Misc.
Publ #37, 22 pp.
9. Kurt, C.E. and Johnson, R.C., Jr., 1982,
Permeability of Grout Seals Surrounding
Thermoplastic Well Casing: Ground
Water, Vol. 20, no. 4, p. 415 - 419.
10. Lamb, B. and T. Kinney, 1989,
Decommissioning Wells - Techniques
and Pitfalls in Proceedings of the Third
National Outdoor Action Conference on
Aquifer Restoration, Ground Water
Monitoring and Geophysical Methods,
National Water Well Association,
Dublin, Ohio, p.217 - 228.
11. Lutenegger, A. J., and DeGroot, D. J.,
994, Hydraulic Conductivity of Borehole
Sealants in D.E. Daniel and S.J.
Trautwein (eds.), Hydraulic
Conductivity and Waste Contaminant
Transport in Soils, ASTM STP 1142,
Philadelphia, Pennsylvania, p. 439-460.
12. Michigan Department of Public Health,
Michigan Water Well Grouting Manual,
1988, 83 pp.
13. Portland Cement Association, 1988.
Design and Control of Concrete
Mixtures. 205 pp.
14. Smith, S.A., 1994. Well and Borehole
Sealing: Importance, Materials,
Methods, and Recommendations for
Decommissioning. EPA - 542/K94/005.
Wisconsin Water Well Association. 69
pp.
15. U.S. Environmental Protection Agency,
1975, Manual of Water Well
Construction Practices, EPA - 570/9-75-
001. 156 pp.
16. U.S. Environmental Protection Agency,
March 1991, Handbook of Suggested
Practices for the Design and Installation
of Ground-Water Monitoring Wells,
EPA- 600/4-89/034. 221 pp.
17. Wyo-Ben Inc., 1999, Groundwater &
Mineral Exploration Products Brochure.
Billings, Montana.
Well Abandonment Handbook
Arizona Department of Water Resources 13
APPENDIX A – A.A.C. R12-15-816, The ADWR Well Abandonment Rule
R12-15-816. Abandonment
A. Well abandonment shall be performed
only by a licensed well drilling
contractor or single well licensee.
B. Except as provided in subsection (F) of
this Section, the owner of a well shall
file a notice of intent to abandon the well
prior to abandonment, on a form
prescribed and furnished by the Director,
which shall include:
1. The name and mailing address of the
person filing the notice.
2. The legal description of the land upon
which the proposed well to be
abandoned is located and the name and
mailing address of the owner of the land.
3. The legal description of the location of
the well on the land.
4. The depth, diameter and type of casing
of the well.
5. The well registration number.
6. The materials and methods to be used to
abandon the well.
7. When abandonment is to begin.
8. The name and well drilling license of the
well drilling contractor or single well
licensee who is to abandon the well.
9. The reason for abandonment.
10. Such other information as the Director
may require.
C. The Director shall, upon receipt of a
proper notice of intent to abandon, mail
a well abandonment authorization card
to the designated well drilling contractor
or single well licensee.
D. Except as described in subsection (F) of
this section, a well drilling contractor or
a single well licensee may commence
abandoning a well only if the driller has
possession of an abandonment card at
the well site, issued by the Director in
the name of the driller, authorizing the
abandonment of that specific well or
wells in that specific location.
E. Within 30 days after a well is abandoned
pursuant to this Section, the well drilling
contractor or single well licensee shall
file with the Director a Well
Abandonment Completion Report on a
form prescribed and furnished by the
Director which shall include the date the
abandonment of the well was completed
and such other information as the
Director may require.
F. In the course of drilling a new well, the
well may be abandoned without first
filing a notice of intent to abandon and
without an abandonment card. If the
well is abandoned pursuant to this
subsection without first filing a notice of
intent to abandon and without an
abandonment card, the well drilling
contractor or single well licensee shall
provide the following information in the
Well Abandonment Completion Report:
1. The legal description of the land upon
which the well was abandoned and the
name and the mailing address of the
owner of the land.
2. The legal description of the location of
the well on the land.
3. The depth, diameter and type of casing
prior to abandonment.
4. The well registration number.
5. The materials and methods used to
abandon the well.
Well Abandonment Handbook
14 Arizona Department of Water Resources
6. The name and well drilling license
number of the well drilling contractor or
single well licensee who abandoned the
well.
7. The date of completion of the
abandonment of the well.
8. The reason for abandonment.
9. Such other information as the Director
may require.
G. The abandonment of a well shall be
accomplished through filing or sealing
the well so as to prevent the well,
including the annular space outside the
casing, from being a channel allowing
the vertical movement of water.
H. A well not penetrating an aquifer shall
include a surface seal which shall be
accomplished as follows:
1. If the casing is removed from the top 20
feet of the well, a cement grout plug
shall be set extending from two feet
below the land surface to a minimum of
twenty feet below the land surface, and
the well shall be backfilled above the top
of the cement grout plug to the original
land surface.
2. If the casing is not removed from the top
ten feet of the well, a cement grout plug
shall be set extending from the top of the
casing to a minimum of twenty feet
below the land surface, and the annular
space outside the casing shall be filled
with cement from the land surface to a
minimum of twenty feet below the land
surface.
I. In addition to the surface seal required in
subsection (H):
1. A well penetrating a single aquifer
system shall be filled with cement grout,
concrete, bentonite drilling muds, clean
sand with bentonite, or cuttings from the
well.
2. A well penetrating a single or multiple
aquifer system with vertical flow
components shall be sealed with cement
grout or a column of bentonite drilling
mud of sufficient volume, density, and
viscosity to prevent fluid communication
between aquifers.
J. Materials containing organic or toxic
matter shall not be used in the
abandonment of a well.
K. The owner or operator of the well shall
notify the Director in writing no later
than 30 days after abandonment has been
completed. The notification shall
include the well owner’s name, the
location of the well, and the method of
abandonment.
Well Abandonment Handbook
Arizona Department of Water Resources 15
APPENDIX B – Definitions
For the purposes of this Handbook, the
following terms have the following
meanings:
Acid Resistant Cement (also known as
Pozzolanic cement) (generic mixture):
means a cement mixture that has improved
resistance to corrosive fluids. Acid resistant
cement is developed by adding silicious
materials, pozzolans, to Portland cement.
Pozzolans from both natural materials of
volcanic origin such as perlites (volcanic
ashes), heat treated clays, shales, tuffs,
opaline cherts and diatomaceous earth, and
artificial materials consisting of by-products
from glass factories, furnace slag, and fly
ash may be used. A common mixing ratio is
74 pounds of pozzolans per 94 pound sack
of cement and not more than ten (10) gallons
of water per sack of cement. If perlites are
used, 2 to 6 percent of bentonite by weight is
needed to keep the perlite from floating.
Acid resistant cement is typically
recommended for well abandonment
material in areas where low pH groundwater
is encountered (such as near some mine
sites).
Aggregate (generic mixture): means sand
or gravel with particle size up to ¼ inch.
Annular Space: “means the space between
the outer well casing and the borehole wall.
An annular space also means the space
between an inner well casing and an outer
well casing.” A.A.C. R12-15-801(1)
Aquifer: “means an underground formation
capable of yielding or transmitting usable
quantities of water.” A.A.C. R12-15-801(2)
Aquifer Boundary: means a vertical
change in aquifer properties indicated by a
difference in hydraulic conductivity between
aquifer layers that is at least greater than two
orders of magnitude (100 times greater).
Bentonite “means a colloidal clay
composed mainly of sodium
montmorillonite, a hydrated aluminum
silicate.” A.A.C. R12-15-801(5)
Cement Grout or Grout: “means cement
mixed with no more than 50 percent sand by
volume, and containing no more than six
gallons of water per 94 pound sack of
cement.” A.A.C. R12-15-801(15)
Cement grout is sometimes referred to as
“sand-cement grout”, when sand is in the
mixture.
Grout is often used as a synonym for slurry
which is a generic term that means a thin
mixture of liquid, commonly water, and any
of several finely divided substances such as
cement or clay particles.
Cement-Bentonite Grout (generic
mixture): means a mixture of cement,
bentonite and water at a ratio of 6.5 gallons
of water per each 94 pound sack of cement
with not more than 3 to 5 pounds of
bentonite per sack of cement.
Concrete or Concrete Grout (generic
mixture): means a mixture of cement, sand,
coarse aggregate and water, with not less
than seven (7) 94 pound sacks of cement per
cubic yard of mixture and not more than
seven (7) gallons of water per sack of
cement.
Exploration Well: “means a well drilled in
search of geophysical, mineralogical, or
geotechnical data”. A.A.C. R12-15-801(13)
Free-Product Contamination: means any
known hazardous substance that is
essentially immiscible (non-soluble) in
water. Some typical examples of free-product
contamination are gasoline and
carbon tetrachloride.
Well Abandonment Handbook
16 Arizona Department of Water Resources
Hazardous Substance: has the same
meaning prescribed by A.R.S. § 49-201.
High-Solids Bentonite Grout (granular or
powder mixture) with a minimum of 15%
solids by weight: means a mixture of
granular bentonite or powder bentonite that
yields a grout that has a minimum 15%
bentonite solids by weight.
High-solids bentonite grout with a minimum
of 15% solids by weight can be prepared
from a mixture of granular bentonite
(nominal 8 to 20-mesh particle size), water
and polymer at a ratio of one hundred-fifty
(150) pounds of granular bentonite and one
hundred (100) gallons of water premixed
with one (1) quart of polymer.
High-solids bentonite grout with a minimum
of 15% solids by weight can also be
prepared from a mixture of bentonite
powder (nominal 200-mesh particle size)
and water at a ratio of fifty (50) pounds of
dry bentonite powder and thirty-four (34)
gallons of water.
High-Solids Bentonite Grout (granular or
powder mixture) with a minimum of 25%
solids by weight: means a mixture of
granular bentonite or powder bentonite that
yields a grout that has a minimum 25%
bentonite solids by weight.
High-solids bentonite grout with a minimum
of 25% solids by weight can be prepared
from a mixture of granular bentonite
(nominal 8 to 20-mesh particle size), water
and polymer at a ratio of one hundred-fifty
(150) pounds of granular bentonite and fifty-four
(54) gallons of water premixed with
one (1) quart of polymer.
High-solids bentonite grout with a minimum
of 25% solids by weight can also be
prepared from a mixture of bentonite
powder (nominal 200-mesh particle size)
and water at a ratio of fifty (50) pounds of
dry bentonite powder and eighteen (18)
gallons of water.
High-Solids Bentonite Chips: means chips
of coarse bentonite ranging in size from 0.25
to 0.75 inch.
High-Solids Bentonite Pellets: means
pellets of fine compressed bentonite (200-
mesh) ranging in size from 0.25 to 0.50
inch.
Neat Cement or Neat Cement Grout
(generic mixture): means a mixture of one
(1) 94 pound sack of cement with not more
than six (6) gallons of clean water.
Pressure Grouting “means a process by
which a grout is confined within the
borehole or casing of a well by the use of
retaining plugs, packers, or a displacing
fluid by which sufficient pressure is applied
to drive the grout into and within the annular
space or interval to be grouted.” A.A.C.
R12-15-801(23)
Sand-Bentonite Grout (generic mixture):
means a mixture of equal parts sand and
bentonite by volume with slightly more than
one (1) gallon of water per pound of sand.
Sand-Cement Grout (generic mixture):
means a mixture of one 94 pound sack of
Portland cement, sand and water in the
proportion of not more than one (1) part by
volume of sand to one (1) part of cement
with not more than six (6) gallons of water
per 94 pound sack of cement.
Sealing: means the conscious effort to
construct a positive permanent barrier within
a well that restricts or prohibits the vertical
movement of groundwater and/or any other
fluids or materials.
Vadose Zone Well “means a well
constructed in the interval between the land
surface and the top of the static water level.”
A.A.C. R12-15-801(26)
Well Abandonment Handbook
Arizona Department of Water Resources 17
Vadose Zone Contamination Issue: means
any hazardous substance that is found in the
vadose zone at or in the vicinity of the well
at concentrations that exceed established
state or federal standards.
Water Quality Contamination Issue:
means any known hazardous substance that
is found in groundwater at or in the vicinity
of the well at concentrations that exceed
established state or federal standards.
Well: means any man-made opening in the
earth through which water may be
withdrawn or obtained from beneath the
surface of the earth including: 1) all water
wells, monitor wells and piezometer wells;
2) geothermal wells for which the rules of
the Arizona Oil and Gas Commission do not
require the reinjection of all water associated
with the geothermal resource to the
producing strata; and 3) all exploration wells
and grounding or cathodic protection holes,
except those that are less than 100 feet in
depth and do not encounter groundwater.
The question and answer section of this
Handbook contains additional information
concerning the types of wells that are
subject to ADWR’s well abandonment rule.
Well Abandonment “means the
modification of the structure of a well by
filling or sealing the borehole so that water
may not be withdrawn or obtained from the
well.” A.A.C. R12-15-801(28)
Well Abandonment Handbook
18 Arizona Department of Water Resources
Well Abandonment Handbook
Arizona Department of Water Resources 19
APPENDIX C – Questions and Answers about the Abandonment
Handbook
Why was it necessary to provide a separate
well abandonment Handbook when there is
an existing well abandonment rule?
ADWR has become aware of some
misunderstanding among well owners and
well drillers concerning the requirements of
the well abandonment rule, A.C.C. R12-15-
816. This Handbook is intended to provide
guidance to well owners and well drillers on
what is required by the rule.
In addition, this Handbook describes the
procedures and materials that should be used
to abandon wells not detailed in the rule.
The well abandonment rule requires a
person abandoning a well to fill or seal the
well in order to prevent the well, including
the annular space outside the casing, from
being a channel allowing the vertical
movement of water. Any well owner or
well driller who abandons a well in
compliance with this Handbook will be
deemed to be in compliance with this
requirement.
Q. What types of wells are subject to
ADWR’s well abandonment rule?
A. The well abandonment rule applies to
man-made openings in the earth through
which water may be withdrawn or
obtained from beneath the surface of the
earth, including all water wells, monitor
wells and piezometer wells.
The well abandonment rule also applies
to geothermal wells for which the rules
and regulations of the Arizona Oil and
Gas Commission do not require the
reinjection of all waters associated with
the geothermal resource to the producing
strata, as well as exploration wells and
grounding or cathodic protection holes
greater than 100 feet in depth (regardless
of whether they intercept groundwater).
Q. What types of openings in the earth are
not subject to ADWR’s well
abandonment rule?
A. The well abandonment rule does not
apply to:
1. man-made openings in the earth not
commonly considered to be wells,
such as construction and mining
blast holes, underground mines and
mine shafts, open pit mines, tunnels,
septic tank systems, caissons,
basements, and natural gas storage
cavities;
2. an injection well or vadose zone well
that is subject to regulation by the
Arizona Department of
Environmental Quality (ADEQ),
provided that ADEQ has issued a
letter or other document asserting
explicit regulatory authority over the
well;
3. oil, gas, and helium wells drilled
pursuant to the provisions of Title
27, Arizona Revised Statutes (wells
regulated by the Arizona Oil and Gas
Commission); and
4. boreholes in the earth less than 100
feet in depth which are made for
purposes other than withdrawing or
encountering groundwater (such as
exploration wells and grounding or
cathodic protection holes less than
100 feet in depth), except that if
groundwater is encountered in the
drilling of the borehole, the well
abandonment rule will apply.
Although the well abandonment rule
does not apply to these types of wells
and boreholes, it is nevertheless
recommended that unused wells or
Well Abandonment Handbook
20 Arizona Department of Water Resources
boreholes that are not regulated under
ADWR’s well abandonment rule be
abandoned in a manner that will protect
the aquifer.
Q. What is the benefit of abandoning an
unused well, as opposed to capping the
well (which is also allowed under
ADWR’s rules)?
A. Proper well abandonment is favored
over well capping for both
environmental and safety reasons.
Unused and unabandoned wells
constitute actual or potential
environmental hazards because they can
serve as vertical conduits for hazardous
substances to cross-contaminate
aquifers. For example, during the last
several decades, serious and costly
vertical cross-contamination of a
multiple aquifer system has occurred
through unabandoned conduit wells at
the Indian Bend Wash Superfund site in
Scottsdale, Arizona. Owners of unused,
unabandoned wells should also realize
that they may be held legally responsible
for secondary contamination if it is
demonstrated that their well served as a
conduit for vertical cross-contamination
of an aquifer system.
Public safety issues also favor well
abandonment over well capping.
Capped wells are often tampered with,
and once the well cap is removed there is
a real danger for humans or animals to
fall into the well, or for the well to be
used for the illegal disposal of hazardous
materials.
Q. Why is it generally required to run a
video log to determine the condition of
the casing perforations in areas where
water quality contamination exists if
the casing is not ripped?
A. Because significant conduit flow can
occur through the annular space outside
the casing, it is essential to seal this
pathway to prevent potential vertical
cross-contamination. Therefore, when
water quality contamination issues exist,
unless the well casing is removed or the
casing is re-perforated over its entire
length from 20 feet above the highest
historic water level to the total depth of
the well, the well owner must run a
video log to determine whether the grout
material can flow through the casing
perforations and seal the annular space
outside the casing.
Video logging and/or casing re-perforation
may not be required in the
case of the abandonment of recently
constructed monitor wells. However,
that determination must be made on a
case-by-case basis.
In areas where water quality
contamination issues do not exist, if the
casing is not ripped, a video log is
recommended, although not required, to
determine perforation conditions. It is
important to make sure that the well and
the annular space outside the casing are
properly abandoned even when there are
no current water quality contamination
issues. This is because the water could
become contaminated in the future.
It should also be pointed out that
additional benefits can be derived from
running a video log. Those benefits may
include: the determination of the
structural integrity of the well casing, the
presence of casing anomalies and
obstructions, the presence of perched or
cascading water, etc. This information
can be very important in developing an
effective abandonment design.
Q. Under what circumstances is it
permissible to use drill cuttings to
abandon a well?
Well Abandonment Handbook
Arizona Department of Water Resources 21
A. In the course of drilling a new well, the
well may be abandoned using drill
cuttings from the well being drilled only
if the well does not penetrate an aquifer
or the well penetrates a single aquifer
only, with no vertical flow components.
Drill cuttings may only be used to
abandon the well from which they were
originally removed. Drill cuttings may
not be used to abandon wells or
boreholes that have water quality and/or
vadose zone contamination issues.
Q. How can it be determined whether
vertical flow components exist in an
aquifer or aquifer system?
A. The determination of vertical flow
conditions in an aquifer can be a
challenging task. However, vertical
flow conditions can be assessed by
evaluating water level data collected in
piezometers or monitor wells that are
completed at different depths within an
aquifer or aquifer system at the same
location. Vertical fluid movement can
also be evaluated in non-pumping wells
using various geophysical logging
techniques such as flowmeter logging,
spinner logging or tracer logging. The
observation of cascading water or water
seeping into a non-pumping well below
static level is a clear indication of
vertical flow conditions within the well.
Because unit-specific water level data
are typically unavailable, and
geophysical logging may be impractical
or too costly, it is best to assume that
most aquifers or aquifer systems have
some component of vertical flow, and
well abandonment methods and
materials should be chosen accordingly.
Q. What should I do if I have further
questions concerning a well
abandonment project?
A. Contact ADWR Hydrology Division at:
602-417-2400
(Phoenix metro area)
1-800-352-8488
(outside metro Phoenix)